The present invention relates to a switch hinge having a first hinge wing, which accommodates a switch operable by a lever, having a second hinge wing and having a shaft. The shaft, in the operative position, is non-rotatably connected with the second hinge wing and, on its circumference, has a switch groove which extends in the direction of the shaft axis and into which an operating pin connected with the lever dips in a predetermined swivelling position between the two hinge wings. The lever extends parallel to the longitudinal axis of the shaft and is swivellable with respect to the shaft as well as being loaded by a spring in the direction of the shaft and being situated in the region of a control cam or control pin of the switch.
Switch hinges of the above-mentioned type are known per se and are used, for example, as hinges for protective hoods on machines, shelter doors or the like. In this case, the overall construction of a switch hinge is designed such that the on-position of the switch exists only when the protective hood or the shelter door is closed. In this situation, the operating pin connected with the lever engages in the switch groove of the shaft.
When the protective hood or shelter door is now opened up, a resulting rotation of the shaft has the effect that the operating pin is pressed out of the switch groove and is supported on the outer circumference of the shaft. This, in turn, results in a lever operation and thus in an operation of the control cam or of the control pin of the switch, so that the switch is changed into its off-position.
Because of the many different installation situations for switch hinges of the above-mentioned type occurring in practice, it must be ensured that the reaching of the on-position for the switch will always only be possible when a protective hood or shelter door takes up its closed position. In this case, these closed positions may definitely result in many different mutual angular positions of the two hinge wings. For this reason, switch hinges of the above-mentioned type had so far in each case been manufactured according to order instructions.
It is an object of the present invention to provide a switch hinge of the above-mentioned type which can be used universally and can be adapted to every conceivable application case.
According to the invention, this object is achieved in that, in a preassembled condition, in which the operating pin rests in the switch groove, the shaft is secured by a lock against rotation with respect to the first hinge wing, and the second hinge wing is freely swivellably with respect to the shaft. By means of a fitting screw screwed into the face-side end of the first hinge wing, the shaft can be axially displaced by a predetermined extent out of the preassembled position into the operative position. The shaft is provided with a knurled or otherwise structured ring zone which, when the shaft is displaced in the operative position, is press fitted into a hinge bore of the second hinge wing, for achieving the securing against rotation between the second hinge wing and the shaft.
A switch hinge designed in this manner has considerable advantages in practice. Independently of the later concrete usage case, such a switch hinge can be assembled at the factory in its preassembled position. This switch hinge can now be fastened at the site, for example, to a stationary machine part and a protective cover movable with respect to the latter. In each case, the operating pin of the lever rests in the switch groove of the shaft, whereby the on-position of the switch is defined. In this case, it is not important which angular position the two hinge wings take up relative to one another because, in this preassembled position, the second hinge wing is still freely rotatable with respect to the shaft.
After the connection of the switch hinge according to the connection, in the closed position of a protective hood or of a shelter door, the shaft is now axially displaced by the fitting screw into its operative position. In this case, the knurled or otherwise structured ring zone, while achieving a form closure, is pressed into the hinge bore of the second hinge half. Now, a swivelling of the second hinge wing relative to the shaft is not longer possible. Next, the securing, with respect to rotation, by a lock is eliminated between the first hinge wing and the shaft, and the hinge can be operated. An opening of the protective hood or of a shelter door now has the result that the shaft is rotated with respect to the first hinge wing and, as a result, the operating pin connected with the lever is moved out of the switch groove. Thus, as mentioned above, the switch takes up its off position.
A hinge switch according to the invention can therefore be used universally and, in practice, can be adjusted without any problem for any conceivable application case.
Additional characteristics of the invention are described.
Other aspects of the present invention will become apparent from the following detailed description of the invention, when considered in conjunction with accompanying drawings.